Properties of waves

PROPERTIES OF WAVES
PLAN:
1. Waves.
2. . Elastic waves.
3. gravitational waves and their properties.

Waves are changes in the state of a substance or medium propagating in space with a finite speed. During the propagation of waves, energy is transferred from one point of space to another point, but the particles do not move. Different waves correspond to different mechanical, thermal, electromagnetic state changes. Elastic wave, surface wave, and electromagnetic wave types are common. Propagation of elastic deformations in gas, liquid and solid bodies is called elastic wave. A sound wave and a seismic wave from the Earth's crust are special cases of an elastic wave. Waves propagating along the boundary surface of two media are surface waves. Electromagnetic waves—particularly radio waves, light waves, ultraviolet waves, X-rays, and gamma waves—consist of propagating alternating electromagnetic fields. There are also gravitational waves. Wave processes are found in almost all fields of physical phenomena. The study of waves is important for physics and engineering.

Movements that repeat at certain time intervals are called oscillations. If the vibrations are along the direction of wave propagation, they are called longitudinal waves, and if they are perpendicular to the direction of propagation, they are called transverse waves. When longitudinal waves propagate, the particles of the medium spread along the direction in which the wave propagates. In transverse waves, the particles of the medium vibrate in a direction perpendicular to the direction of the waves. Elastic waves in gases and liquids are longitudinal waves. Elastic waves in solids, including Earth's seismic waves, can be transverse waves rather than longitudinal waves. The vibrations of the medium particles are perpendicular to the direction of wave propagation. Electromagnetic waves are transverse waves, in which the directions of the oscillating electric field and magnetic field strengths are perpendicular to the direction of wave propagation. The source of mechanical waves is finite bodies and substances that tend to change their state under the influence of external force, and the source of electromagnetic waves is the oscillating circuit and moving charges. When studying the properties of waves, its parameters are used, i.e. amplitude, length, frequency, speed of propagation, phase, wave vector and other quantities. A change in the frequency, phase, or amplitude of waves is called wave modulation. Depending on the change of a specific parameter, liquid modulation occurs - frequency modulation, phase modulation, amplitude modulation.
Any wave of arbitrary shape can be considered a sum of harmonic waves. A system of waves with very close frequencies in a limited small part of space at each instant of time is called a wave group or wave packet. In general, a wave front and a wave packet, for example, have a maximum amplitude, propagate with different speeds. The speed of the wave front is a constant phase speed, so this speed is called the phase speed. The specific amplitude velocity associated with a wave packet is called the group velocity. In wave propagation, energy propagates with group velocity.
Interference, diffraction, refraction, return, polarization and other phenomena for different waves follow the same laws. Gravitational and gluon types of waves have not been confirmed in the experiment.
Wavelength is the distance between two consecutive, in-phase oscillating points of an oscillating motion propagating in a certain direction in a medium. If the vibration is propagating in the medium with speed v, the wavelength X is equal to the propagation distance of the wave in one period G, i.e. XqvT. Depending on the physical nature of the waves, their wavelength can have values ​​from several kilometers to certain fractions of angstroms (lA q10~10 m). In a homogeneous medium and air, sound and electromagnetic waves propagate with a constant speed (itq331 m/s; s q300000 km/s), so the wavelength depends on the wavelength of the oscillation period. We are all familiar with the adjectives "longitudinal" and "transverse". And they need only familiar and inactive everyday life. But when it comes to waves of anything - air, solid matter or electromagnetic fields, it is a number of frequent questions. day, listening to the word of the world "transverse and longitudinal waves," the average person is a sinus. Of course, the vibration in the water is visible and visible, so life gives a hint. Complex and diverse: bo There are horizontal and transverse waves
Any field, gas, solid matter, vibration occurs when energy transfer from one point depends on the middle, they are called waves. Due to the fact that the propagator of the vibration is a step wave at a variable point and any movement never varies with the distance from the source. An important point to always remember: the particles of the environment move their energy through their vibrations, and do not remain in a balanced state. In addition, if you look at the inspection process, it will be clear that the particles are not changed, and the court group is concentrated in one volume. This is possible with a simple rope: if there is a constant and another (in any plane) production of waves, the whole particles are moved as a result of the wave, the rope is rarely materially destroyed. We know that there are many aspects of physics that many people find difficult to understand. One of these aspects is gravitational waves. These waves were predicted by the scientist Albert Einstein and discovered 100 years after their prediction. They represent a breakthrough for science in Einstein's theory of relativity.
That's why we dedicate this article to tell you everything you need to know about gravitational waves, their properties and their importance. We are talking about a representative in space that is created by an accelerated massive body that directs energy in all directions with the help of light. The phenomenon of gravitational waves allows spacetime to stretch without returning to its original state. In addition, it produces microscopic artifacts that can only be detected in advanced scientific laboratories. All gravity is capable of scattering from light
They produced energy that produced any, two or more transferable amounts of energy. This is the event that causes spacetime to expand to its original state. Made a very important contribution to the study of space through the discovery of gravitational waves. With this, it is possible to offer space assistant and other models for all its tools. Although one of Albert Einstein's last hypotheses in the theory of relativity was the description of gravitational waves, they were discovered a century later. Thus, one can see the measures of these gravitational waves that Einstein pointed out. According to this scientist, this is due to a mathematical derivation that states that waves in this case cannot be extinguished by any object or signal faster than light.
A century later, in 2014, the BICEP2 observatory announced the discovery of gravitational waves and terraces created during the expansion of the universe. Big Bang. After a short time, it was possible to reject this news, seeing that it was not true.
A year later, scientists of the LIGO experiment managed to detect these waves. So, they made sure they visited to break the news. So even though the Discovery was in 2015, they announced it in 2016. Let's look at the most reliable support that has made gravitational waves one of the most important discoveries in physics in recent years. These have changed the changes that have taken place, to the extent that they change it without letting it go back to its original state. The main characteristic is that any kind of lighting is possible for them. They are transverse waves and can be polarized. This means that it also has a magnetic function.
These waves can carry energy at high speeds and over long distances. Perhaps, about one of the doubts that the shots may appear, it may not be complete. They can appear at different frequencies depending on the intensity of each.
Although it is not fully understood, there are many scientists who are trying to determine if it is caused by gravitational waves. Let's see how they stack up: Now we want to briefly analyze how LIGO scientists detected waves in this case. We can produce them in microscopic size and only as high-tech equipment. I must also remember that it is too delicate for him. They are known as interferometers. They are several kilometers apart and consist of an L-section tunnel system. Lasers pass through these kilometer-long tunnels, which bounce off mirrors and interfere with passage. When a gravitational sling occurs, it can be manipulated by warping space-time. Stable formation occurs inside the mirrors in the interferometer.
Other things that can also detect gravitational waves are radio telescopes. Such radio telescopes can measure light from pulsars. In terms of the importance of the detection of scattered waves, it allows a better shot of the universe. And thanks to these waves, you can get good vibrations that expand in space. The discovery of these waves made it possible for the universe to be deformed and all deformations to expand and contract in a wave pattern throughout space.

It should be noted that in order for gravitational waves to appear, violent processes such as collisions of black holes must be created. Events and cataclysms occur in space thanks to the study of these waves, from which information can be obtained. Collecting all the phenomena of physics helps to consider many laws. With this, a lot can be learned about the cosmos, its origin, and how stars are deformed or destroyed. All of this information is also used to learn more about black holes. An example of a gravitational wave is found in the explosion of a star, the collision of two meteorites, or the formation of black holes. It can also be found in a supernova explosion.

I hope that with this information you will learn more about gravitational waves and their properties. If an oscillating body is placed in an elastic medium, neighboring particles will start to oscillate with it. The movement of these particles causes the particles that follow them to vibrate, and so on. After some time, the entire elastic medium begins to oscillate. So, the farther the particle is from the main oscillating body, the later its oscillation starts, in other words, the particles oscillate in different phases. The propagation of vibration in the medium of motion is called a wave. An example of a wave process can be waves that are scattered by a stone falling on the surface of water. The direction of wave propagation is called a ray. If the particles of the medium vibrate perpendicular to the light, such a wave is called a transverse wave, if the particles vibrate parallel to the light, such waves are called longitudinal waves. An example of a transverse wave is a wave on the water surface, and an example of a longitudinal wave is sound waves. This waveform is reminiscent of the oscillation equation (2), but with a file difference. The equation of oscillations is the displacement of a given particle at a faster time b. And the wave graph shows how the quality of the source (all) particles for a given time depends on the distance to the displacement x. Let's consider the displacement of point A, which is located at a distance from point O, the source of displacements. If the particle s is oscillating first, then the particle A will oscillate sec, where is the time of propagation of vibrations from point O to point A, in other words . Then the equation of vibration of particle A will have the form: If the wave is not sinusoidal, it consists of the sum (superposition) of several sinusoidal waves whose frequencies lie in the interval, then this wave will be in the form of a water (packet) (see Fig. 3 ) ).
For such a wave, in addition to the phase velocity, another group velocity contribution is introduced. Group velocity refers to the distribution of energy in space through water. This velocity represents the water amplitude in space, and it can be controlled by the formula: So, the intensity of the wave is proportional to the density of the medium, its speed, the square of the frequency and the square of the amplitude.
Phase and group speed. The propagation speed of a sinusoidal (harmonic) wave is called phase speed. Since there is a phase, we find the velocity of propagation of a given displacement along the coordinate with time: Since F=0, then the phase velocity is equal to: In this formula, - is the coefficient related to the elastic property of the medium. - the density of the medium. In particular, for longitudinal waves in a rigid body; for transverse waves (E-Young modulus)
We determine how the displacement x of the particles involved in the process and the distance of these particles to the point O, the source of vibrations, will be the relationship for time.
For clarity, we consider a transverse wave. Let us assume that the oscillations of the source are harmonic:
This expression shows that period and frequency are inversely related to each other.
Oscillation amplitude is the quantity equal to the maximum deviation distance from the stable state of the oscillating point or system.
Amplitude is denoted by the letter A and its unit is meter (m).
[A] = 1 m
Time-dependent oscillations of amplitude A are divided into two types, non-fading and decaying oscillations.
A vibration whose amplitude remains unchanged over time is called a constant vibration. A vibration that decreases with time is called a decaying vibration.
The quantity that characterizes the position of the oscillating point and the direction of movement is defined as the oscillation phase.where A-oscillation amplitude, - angular frequency. After the beginning of the oscillations in the source, other points of the environment also operate with the same amplitude and frequency, only with a little delay. In Figure 1, a sinusoidal wave appears. Oscillations and the waves they create are the basis of a very widespread process in nature and technology. Examples of such processes are the oscillation of a clock pendulum, alternating current in a circuit, sound, and the like. They shake the tree, and the strings of the music also shake. In the technique, the piston of internal combustion engines vibrates, the fuselage of an airplane, and the body of a car also vibrate.
In the life of our planet, there is also a vibrational movement. And it is the rise of water in the oceans and seas, and the place of water, and the movement of the earth. A living organism also vibrates. And it is the heartbeat, the movement and movements of the vocal cords.
There are two types of vibrations depending on their physical nature. And they are mechanical and electromagnetic vibrations. A vibrating body is always connected to other bodies and together with them they form a system. The resulting system is considered an oscillating system.
Oscillating motion or oscillation refers to periodic motion. Different types of vibrations created in technology and nature are subject to the same clothes. A changing electric current in the loop creates a changing magnetic field. At the same time, the electric field of the capacitor also changes. For this purpose, the charges of a considered capacitor and the current in the circuit are freely oscillating free electromagnetic oscillations. The energy of these oscillations is equal to the electrical energy of the currently charged capacitor. Then, the electromagnetic oscillations in the circuit gradually decrease as the Joule-Lance heat is dissipated as the current flows. After that, the energy of electromagnetic vibrations dissipates and fades. In order to generate continuous electromagnetic oscillations, energy must be supplied to the circuit from the outside to replenish the energy lost due to Joule-Lens heat. In this case, we are no longer dealing with free, but strong electromagnetic vibrations. In order to create such oscillations, it is necessary to connect a current source with a periodic change of the EIUK to the contour of the oscillator (Fig. 4).
In modern physics, the physics of vibration is distinguished as a special field, in which different vibrations are considered from a single point of view. Controls of the physics of vibrations form the theoretical basis of mechanical transmissions, alternating current, electrical engineering and radio engineering.
One of the serious signs of oscillatory motion is its periodicity. Any periodic repetitive movement is characterized by physical quantities: amplitude, period, frequency, phase, circular or cyclic frequency.
Oscillation period is a physical quantity equal to the time taken for one complete oscillation. The oscillating cycle works with the letter T and the motion with the formula: Not the oscillations or free oscillations of pendulums from equilibrium and not acted upon by rock forces. Free oscillations of pendulums can only be harmonic oscillations in the absence of friction. There are fluctuations in the contour. Therefore, electric field energy is converted into magnetic field force and installation, magnetic field energy is converted into electric field energy, that is, electromagnetic vibrations occur. If the resistance of the circuit is zero, the process of converting electric field energy into magnetic field energy and its opposite can continue indefinitely, that is, inexhaustible electromagnetic oscillations are created. These vibrations are said to be spontaneous or free vibrations because they occur without structural forcing forces.
A pendulum is any rigid body that oscillates around an arbitrary axis that does not pass through the center of gravity.
The simplest type of pendulum is a mathematical pendulum.
A mathematical pendulum is a system consisting of a material point with a known mass, on which a weightless load is transferred to an inextensible string.
A pendulum consisting of a string suspended from a very small ball can practically be a mathematical pendulum Since the wave is a support (here is the linear frequency, T is the period of oscillation), if we put in equation (3) and is a quality estimate, the wave equation will have the following form:
Here it is done as wave number and it means how many waves are received in the distance.
When a wave propagates, because the particles vibrate, the wave has energy, and it propagates with the wave. The amount of energy passing through a unit of surface per unit of time is considered to be the intensity of the wave (or the density of energy detection). Let's mark with it. Let's say that there are particles in the volume of 1 cm3 of the medium, each of which has a mass .Since each particle has a full energy of harmonic vibration, the total vibrational energy supply of particles per unit volume is equal to. If the wave is not sinusoidal, it consists of the sum (superposition) of several sinusoidal waves whose frequencies lie in the interval, then this wave will be in the form of a water packet see
For such a wave, in addition to the phase velocity, another group velocity contribution is introduced. Group velocity refers to the distribution of energy in space through water. This velocity represents the water amplitude in space, and it can be controlled by the formula:
So, the intensity of the wave is proportional to the density of the medium, its speed, the square of the frequency and the square of the amplitude.
Phase and group speed. The propagation speed of a sinusoidal (harmonic) wave is called phase speed. Since there is a phase, we find the velocity of propagation of a given displacement along the coordinate with time: Since F=0, then the phase velocity is equal to.